Sean Costigan

Sean Costigan (1969-) was a Boston drug dealer.

Biography
Sean Costigan was born in South Boston, Boston, Massachusetts in 1969 to a working-class Irish family, and he was the cousin of Billy Costigan. His family was deeply involved with crime, and Sean became a cocaine dealer, befriending Myles Kennefick (who was later murdered after stealing 20 microprocessors). In 2006, his cousin Billy, now an undercover cop, made contact with Sean in order to re-enter the criminal world, and the two of them later got into trouble with the Costello Mob for dealing drugs on Costello territory in Worcester. However, this gave Billy Costigan the ability to meet Irish Mob boss Frank Costello and infiltrate his organization.